Controlling antibiotic-resistant infections in human health will bring increasing pressure on Irish farms, according to an EU report on the development and implementation of Ireland’s national strategy for tackling antimicrobial resistance.
The main veterinary focus is likely to be on pig farms, according to the new report from the European Commission Directorate-General for Health and Food Safety.
However, the report makes it clear that agriculture is not the main culprit, revealing that total sales of antimicrobials in the Irish veterinary sector are moderate.
This is in contrast to the human health sector in Ireland, in which antimicrobial consumption in the community is higher than the European average (but not in hospitals, where it is lower than average).
The report follows an inspection visit to Ireland last October by EU Health and Food Safety and European Centre for Disease Prevention and Control staff.
They had been invited by the Irish authorities to assist them in development and implementation of Ireland’s strategy for tackling antimicrobial resistance (AMR).
Overall, the report concludes that there is a comprehensive national action plan on AMR (iNAP) for the period 2017-2020.
However, there are no quantitative targets or other indicators for measuring the plan’s outcome.
Actions have been undertaken to address the high consumption of human health antimicrobials in the community, by sensitising general practitioners on prudent usage, and patients who request antibiotics.
In hospitals, antimicrobial stewardship teams were established.
In human health, Ireland’s levels of vancomycin-resistant enterococci among enterococcus faecium bloodstream infections are among the highest in Europe.
A carbapenemase producing enterobacteriaceae (CPE) outbreak in 2017, and subsequent declaration of a national public health emergency, raised awareness.
“However, there is a risk that the focus on one specific pathogen with AMR might lead to a neglect of control of other pathogens with AMR, and of prevention of healthcare associated infections in general,” said EU officials.
They also noted that continuous outcome-based monitoring of infections is not in place, and infection prevention and control staffing remained below necessary levels.
In the environmental sector, monitoring of watch list substances under the Water Framework Directive is being carried out.
The EU officials said the commitment in general in all sectors and at all levels to control of AMR in Ireland is a positive example for other countries.
“There has been progress in AMR control on many levels and, while AMR will likely remain a significant challenge for the country, there are several achievements to build upon for future actions.”
The report then outlines various considerations which could be helpful.
In Irish farming, although sales of antimicrobials are moderate, over 60% are oral antimicrobials, and a significant proportion is attributed to the pig sector, where they are routinely used around the weaning period.
Relatively high use of intramammary tubes for dairy cows in blanket use of antimicrobials at the end of lactation was also noted.
According to the EU report, the DAFM’s national antimicrobial usage database for pigs introduced last November will be extended to other farmed animals.
The data will allow farmers benchmark themselves according to use of antimicrobials, and develop better understanding of usage patterns.
There are already indications from a pig farm pilot project that benchmarking has reduced use of antimicrobials by some of the highest users.
Usage of the database is obligatory in Bord Bia’s pigmeat quality assurance scheme.
AMR national action plan initiatives linked directly to prudent use of antimicrobials are generally voluntary. “Despite this, there are clear cases of farmers not being receptive to the initiatives proposed by the stakeholders to reduce the use of antimicrobials, in particular in relation to the routine use of medicated feed in the pig producers,” noted EU officials.
However, given that new EU legislation will become applicable in early 2022, there is no national plan to strengthen regulations on prescription and use of antimicrobials. Instead, the new veterinary medicine regulation in 2022 will change the regulatory framework around supply and use of antimicrobials, to promote responsible use.
On discovery of high prevalence of ESBL-producing e.coli in broiler samples, DAFM alerted the poultry industry, which took comprehensive actions to reduce use of antimicrobials. This resulted in a noticeable decrease in ESBL-producing e.coli, and in overall resistance levels.
The EU officials were told by one of the biggest poultry processors that the industry has entered a post-antibiotic era, and they have moved from routinely medicating each batch of broilers to not using any antimicrobials in over 90% of the birds they place on the market.
“However, the level of resistance to ampicillin, tetracyclines and sulfamethoxazole in Salmonella, and to tetracyclines in commensal E coli isolates from pigs, remains worryingly high, and highlights the need for urgent actions to be taken by the pig industry,” said EU officials.
They also referred to a first isolation of multidrug-resistant E coli of bovine origin in Ireland on a beef suckler farm with high calf and cow mortality rates.
“This highlighted the risk of the resistant bacteria spreading among the animal population, as well as the risk of colonisation by the strain of the members of the farmer’s family, and the potential further spread to sick patients, due to some of the family members working in the healthcare sector.”
Significant management changes were introduced on the farm, which mitigated these risks and significantly improved the survival rates of the animals.
This case study was presented to the officials, as well as during the One Health Seminar in Dublin in 2018.
According to the European Surveillance of Veterinary Antimicrobial Consumption (ESVAC) report published in October 2019, the total sale of antimicrobials in the Irish veterinary sector in 2017 was 46.6 mg/PCU (population correction unit), compared to a range of 3.1 mg/PCU to 423.1 mg for the other countries contributing data to ESVAC.
But there was a 13% national sales reduction in 2018. Therefore, sales have fluctuated from 41.2 mg in 2018 to 55.9 mg in 2013.
“Worryingly, the figures for the sales of the critically important antimicrobials, especially third and fourth generation cephalosporins, show an increasing trend, accounting for 0.1% of the total sales in 2010 and 0.3% in 2017,” said the EU officials.
Antimicrobials most frequently sold in 2017 were tetracyclines (41.6% of sales in tonnage), followed by penicillins (20.9%) and sulphonamides in combination with trimethoprim (18.1%). Premixes constituted 33.5% and oral remedies 32.6%.
EU officials said there are clear indications that the premixes are routinely used by the pig industry.
“While it is recognised that the infrastructure on the farms is often not suitable, and substantial investments in the drinking systems would be required to allow other forms of dosing, the reliance on medicated feeds has a number of disadvantages, and every effort should be made to revert this situation.
" In addition, the use of medicated feed around the weaning period is often employed to compensate for poor husbandry practices, such as overstocking, or to remedy a poor animal health situation due to lapses in biosecurity on the farms.”
However, Irish authorities responding to the EU report said water based antimicrobial delivery is not without issues, in terms of solubility and precipitation, and targeted feed delivery generally reduces use of antimicrobials.
EU officials said sales of intramammary tubes (1.5 mg/PCU) are not significant, but relatively high use of tubes in dairy cows, often containing CIAs, is a priority issue. Current legislation allows for any vet to prescribe veterinary medicinal products (VMPs) if he or she has sufficient knowledge of the animal or animals.
A requirement to visit the farm does not apply to prescribing an intramammary antimicrobial, if the animal belongs to a herd covered by a co-op’s mastitis control programme — an exemption which covers most the dairy cow population, and covered 45% of lactation tubes and 51% of dry cow therapy tubes in 2015. The EU officials welcomed co-ops actively promoting milk recording, and no longer stocking intramammary tubes containing critically important antimicrobials.
Meanwhile, selective dry cow therapy is being tried in in several herds, based on milk recording results, alongside the CellCheck programme. In addition, milk processors offer financial incentives to promote milk recording, and to support CellCheck veterinary consultation visits.
These initiatives contributed in 2019 to a 20% increase over 2018 in the number of cows being milk recorded. The goal is that farmers will have data-driven prescriptions for intra-mammary tubes and will eventually be able to opt out from blanket use of antibiotics at drying off.
There has already been a 7% reduction in intramammary tube usage over the last eight years (corrected for dairy cow population).
This will improve further, as farmers are now becoming increasingly aware of the benefit of SDCT.
All farmers met by the EU officials highlighted the importance of changing mind-sets and practices. They agreed that the required improvement of farm infrastructure, nutrition, and comprehensive vaccination programmes, will incur substantial costs, but the end result is better farm profitability, and improved welfare and performance of animals.
A pig farmer gave a presentation outlining his two-year journey from managing a herd with multiple health issues and frequent use of medicated feed, to not using any in-feed antibiotics or zinc oxide, and lowering labour costs. This is in contrast to the heavy reliance of the pig industry generally on medicated feed, due to lack of investment in water delivery systems which allow for appropriate treatments at the correct dosage and duration.
Ireland’s AMR programme has not yet been extended to companion animals and horses. However, the National Reference Laboratory here considers resistance in bacteria from companion animals and horses as an at least equal priority to resistance from farmed animals.
Meanwhile, farmers and food industry are conscious of pressure from consumers.
Due to welfare concerns, marketing meat as “antibiotic free” is generally not recommended; Irish state agencies will not support such an approach.
However, six out of the seven main retailers have signed up to Ireland’s responsible antibiotic use initiative.
One of the biggest retailers has shown interest in obtaining data on use of antimicrobials on pig farms.